Superstitions are especially prone to confirmation bias, and they survive because common sense and confirmation bias sometimes reinforce each other. Are black cats unlucky? Cats, black or otherwise, by their nature tend to get underfoot, but we might only remember the black ones who trip us up. I actually live with a lovely black cat named Carla, and I can confirm that she is, on occasion, a menace to my navigation of the stairs. A superstitious person might nod here knowingly,; the fact that Carla is also the only cat in the house, of course, or whether other cat owners have tumbled over their tabbies will mean nothing.
— Tom Nichols, The Death of Expertise